cf-removal: patch registry, pipeline, settings, admin-page, interface

Wires out the Cloudflare Workers AI image provider across the plugin:

- class-image-pipeline.php: drop 'cloudflare' dispatch branch; Runware
  becomes the unrecognised-provider fallback
- class-image-model-registry.php: remove flux-1-schnell/cloudflare row;
  update provider-enum docblocks (runware|openrouter only)
- class-settings-fields-extended.php: remove three CF fields
  (cloudflare_ai_token, cloudflare_account_id, cf_image_via_gateway);
  drop Cloudflare mention from model-picker + NSFW retry descriptions
- class-admin-page.php: remove prautoblogger_cloudflare_ai_token from
  the encrypted-options list
- interface-image-provider.php: retarget preamble @see at Runware +
  OpenRouter; update get_provider_name() example
- class-image-nsfw-blocked.php: generalise preamble (Runware +
  OpenRouter can raise this)

Also cleans stale CF Workers AI mentions in:
class-ajax-handlers.php, interface-model-registry.php,
class-image-nsfw-retry.php, class-open-router-image-pricing.php,
prautoblogger.php.

The Cloudflare AI Gateway path (in class-open-router-config.php,
class-settings-fields.php 'prautoblogger_ai_gateway_base_url',
class-open-router-request-builder.php cache headers) is intentionally
untouched — it fronts OpenRouter and is unrelated to the CF Workers AI
image provider.

includes/admin/class-image-model-registry.php

@@ -22,7 +22,7 @@ class PRAutoBlogger_Image_Model_Registry {
 	 * Each entry contains:
 	 * - id:             Model identifier used in API calls.
 	 * - name:           Human-readable display name.
-	 * - provider:       'runware' | 'openrouter' | 'cloudflare'.
+	 * - provider:       'runware' | 'openrouter'.
 	 * - cost_per_image: Estimated USD cost per generation.
 	 * - capabilities:   Array of capability tags.
 	 * - description:    Short description for the admin UI.
@@ -90,14 +90,6 @@ class PRAutoBlogger_Image_Model_Registry {
 				'capabilities'   => [ 'image_generation' ],
 				'description'    => __( 'OpenAI premium. Photorealistic.', 'prautoblogger' ),
 			],
-			[
-				'id'             => 'flux-1-schnell',
-				'name'           => 'FLUX.1 schnell (Cloudflare)',
-				'provider'       => 'cloudflare',
-				'cost_per_image' => 0.0007,
-				'capabilities'   => [ 'image_generation' ],
-				'description'    => __( 'Legacy Cloudflare fallback. Use Runware FLUX instead.', 'prautoblogger' ),
-			],
 		];
 	}
 
@@ -106,7 +98,7 @@ class PRAutoBlogger_Image_Model_Registry {
 	 * model id is not in the registry.
 	 *
 	 * @param string $model_id Model slug from the admin UI.
-	 * @return string Provider id ('runware' | 'openrouter' | 'cloudflare' | '').
+	 * @return string Provider id ('runware' | 'openrouter' | '').
 	 */
 	public static function provider_for( string $model_id ): string {
 		foreach ( self::get_models() as $model ) {